Email forwarding used to work and stopped working..

Hello! This blog was setup about a month ago and the email forwarding function used to work and I was able to see the link to edit the email addresses to use. However, after changing the DNS to apply for more emails using the same domain, it was all disconnected.

Did I do something wrong? Or was the email forwarding only available to email addresses that do not have an active email already? (Since I bought the email address with gmail, I am not allowed to use the same forwarding)